Flexible abrasive apparatus



NOV. 24, 1970 RADlK (Y 3,541,740

FLEXIBLE ABRASIVE APPARATUS I Filed March 29, 1968 FIG. I FIG. 2

I N VENTOR. ARNOLD RADIK United States Patent Oifice Patented Nov. 24, 1970 I 3,541,740 FLEXIBLE ABRASIVE APPARATUS Arnold Radik, 1616 12th Ave., Moline, Ill. 61265 Filed Mar. 29, 1968, Ser. No. 717,187

Int. Cl. B24b 9/02 US. Cl. 51332 4 Claims ABSTRACT OF THE DISCLOSURE ing uneven surfaces and suflicent rigidity for effective grinding or polishing.

BACKGROUND OF THE INVENTION Field of the invention An improvement in flexible abrasive apparatus for grinding or polishing contoured surfaces.

Description of the prior art Flexible abrasive apparatus and particularly abrasive wheels for grinding or polishing of contoured surfaces of the type herein described can be broken down into two main categories, one, the set-up wheel and two, the flap wheel. The set-up Wheel includes a plurality of canvas discs having their peripheral surfaces coated with an abrasive, the discs are rigidly held in place and together by means of two metal flanges. This wheel is rigid and does not have the flexibility to follow contoured surfaces which in operation requires that the workpiece be brought carefully to one edge of the wheel and only a small strip of the workpiece be ground or polished at each pass. The

abrasive on the set-up wheel is thin in order to provide the wheels with some degree of flexibility thus necessitating frequent replacement. The set-up wheel is not suitably adaptable for automatic grinding or polishing machines because of the above noted disadvantages. The flap wheel includes a plurality of radially extending fabric elements having an abrasive coating thereon. The flap wheel has substantial flexibility but does not have any rigidity which prohibits any pressure to be brought on the workpiece by the wheel. The grinding of the workpiece is difficult and time consuming. The wheel itself, because of the abrasive coating, must be replaced often and fabric elements do not wear uniformly. The present invention provides an improved flexible abrasive apparatus which is durable and utilizes the entire working surface whereby a contoured workpiece can be effectively ground or polished by automatic means.

SUMMARY OF THE INVENTION The present invention provides a novel flexible abrasive apparatus wherein the combination of a plurality of flap members, a plurality of abrasive elements fixed to the periphery of the flap members and means for rigidly supporting the flap members provides apparatus for effectively grinding or polishing contoured surfaces. The present invention will be more clearly understood if described as a flexible abrasive wheel although within the purview of the invention continuous type grinding or polishing belts or similar type apparatus is contemplated. More particularly the invention provides a novel abrasive wheel of the flap type wherein a plurality of flexible fabric flaps are centrally held by means of metal flanges in a rigid fixed position and said flaps have an outer portion defining the periphery of a wheel and each of said flaps having a plurality of abrasive elements fixed or bonded thereto.

The disadvantage of existing grinding or polishing wheels as heretofore described is the lack of an effective combination of wheel flexibility and rigidity for effective grinding or polishing of contoured surfaces. The present invention provides this combination of flexibility and rigidity by means of the novel combination of fabric flaps, abrasive elements and holding means.

The primary object of the present invention is to provide flexible abrasive apparatus for effectively grinding or polishing contoured or flat workpieces. A further object of the persent invention is to provide a flexible abrasive wheel whereby the entire width of the wheel is utilized in grinding or polishing the contoured work surfaces.

A still further object of the present invention is to provide a flexible abrasive wheel having fabric flaps which are durable and readily replaceable. A still further object of the present invention is to provide a flexible abrasive wheel having abrasive elements suitably mounted and constructed to withstand high grinding and polishing pressures. A still further object of the present invention is to provide a flexible abrasive apparatus wherein the centrifugal forces extending the fabric flaps permits greater grinding and polishing pressure to be applied against the apparatus.

A still further object of the present invention is to provide flexible fabric flaps which may be utilized with several types of abrasive apparatus including wheel type and continuous belt type.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational view of the flexible abrasive wheel of this invention partially broken away to clearly show the interior structure.

FIG. 2 is an end elevational view of the flexible abrasive wheel.

FIG. 3 is an enlarged perspective view of the flexible fabric flap with the abrasive elements fixed thereto.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing and in particular to FIGS. l and 2 there is shown a flexible abrasive wheel which is designated generally by the numeral 10. The wheel 10 is a sturdy assembly of elements which are advantageously constructed for rapid assembly and replacement of the individual elements. The wheel 10 comprises a hub 12 having a side plate or flange 14 fixed thereto, a companion flange 16 is disposed to freely move on hub 12. Flanges 14 and 16 have three aligned holes 18 disposed therethrough for three tie bolts 20. Additionally flanges 14 and 16 have a plurality of aligned holes 22 disposed therethrough to receive flexible flaps 24 and holding pins 26. The wheel 10 is maintained at the desired width and held in reasonable rigidity by means of sleeve spaces 28 placed between flanges 14 and 16 and disposed to have tie bolts 20 pass therethrough.

Holding pins 26 are selected to withstand the created centrifugal forces acting on flexible flaps 24 and have one end thereof flared to fit into the countersunk portion 30 of hole 22 in flange 16. Cover plates 32 and 34 are dis posed to be mounted on hub 12 and fastened to the assembly by means of the tie bolts 20. Cover plates 32 and '34 maintain holding pins 26 in a fixed rigid position.

Disposed with the wheel 10 is a pin positioning ring 36. The ring 36 is a thin sheet metal ring designed as a guide in the assembly and insertion of pins 26.

Flexible flaps 24 may be of a fabric construction which may advantageously be a canvas material. The canvas flaps 24 are made of rectangular pieces ofcanvas with=-=- -"thereof--eentrally= held*by =saicflap-holding means,

properly slotted edge. This canvas is especially selected to have the necessary strength and structural characteristics to hold bonded abrasive cubes or chips 38. The weight and size of the abrasive cubes or chips is carefully calculated and selected to conform to necessary wheel speed and proper centrifugal force. The slotted edge of the canvas segment is specially prepared, undercoated, if necessary perforated, or a pile fabric such as velour can be used.

Slots in canvas segments are cut and abrasive cubes are formed in such an order that if every second segment at the assembly of the wheel is turned around, cubes will take staggered positions and a continuous circular line on the wheel is eliminated. Because these canvas segments are held in place on the wheel by pins, the other edge has to be folded and fastened with staples, rivets or sewn together.

The abrasive cubes 38 are to be made of the same mixture as is used for the manufacturing of resinoid wheels. This mixture is pressed at the edge of canvas segments and then cured at proper temperatures. Abrasive cubes 38 can also be made the same way as the set-up wheels are coated. Applying special adhesive on the edge of the canvas segment and covering this with abrasive. This procedure has to be repeated to build up required thickness and then cured at proper temperatures.

It will be understood that the flexible abrasive apparatus which is herein disclosed and described is presented for the purpose of explanation and illustration and is not intended to indicate limits of the invention, the scope of which is defined by the following claims.

I claim:

1. Rotary flexible abrasive wheel of the flap type for grinding or polishing of contoured or flat surfaces comprising flap holding means including a pair of substantially rigid circular flanges,

a plurality of flexible flap elements disposed between said circular flanges and having the inner portion and the outer free end-thereof projecting above the annulus of said flanges, said flap elements including a plurality of segmented sections each having an abrasive element bonded on the outer free end thereof, each of said abrasive elements including a block of abrasive material having a longitudinal slot therein receiving an outer free end of a segmented section, said abrasive elements defining the periphery of the abrasive surface of said abrasive wheel. 2. Rotary flexibleabrasive wheel according to claim 1 wherein said flap holding means includes spacer means disposed between said circular flanges for maintaining said circular flanges in a spaced relationship and fastening means for rigidly holding said circular flanges in a fixed position.

3. Rotary flexible abrasive wheel according to claim 2 including pin means disposed through said pair of circular flanges for holding said flap elements in a fixed position between said flanges.

4. Rotary flexible abrasive wheel according to claim 3 wherein the outer free end of said flap elements are disposed in an overlapping relationship with the adjacent flap element and are disposed to be extended radially on rotation of said abrasive wheel.

References Cited UNITED STATES PATENTS 1,897,971 2/1933 Johnston 51337 2,035,042 2/1936 Bridgman 51337 2,174,385 9/1939 Holmes 51-337 2,522,920 9/1950 Baltes 51-335 2,597,421 5/1952 White 51-334 3,165,867 1/1965 Murray 51-334 v FOREIGN PATENTS 978,183 11/1950 France.

OTHELL M. SIMPSON, Primary Examiner 

